body {
  background-color: #303952;
  display: flex;
  justify-content: center;
  align-items: center;
  width: 100vw;
  height: 100vh;
}

#app {
  width: 400px;
  /* flex-wrap: wrap; */
  display: flex;
  border: solid 10px rgba(255, 255, 255, 0.2);
}
#app div {
  width: 200px;
  height: 200px;
}
#app div:nth-of-type(1) {
  background-color: #f6e58d;
  flex-shrink: 0;
}
#app div:nth-of-type(2) {
  background-color: #ff7979;
  flex-shrink: 1;
}
#app div:nth-of-type(3) {
  background-color: #7ed6df;
  flex-shrink: 3;
}